1. Field of the Invention
The present invention relates to information processing apparatuses, particularly an information processing apparatus used in the registration of information related to a ground tint at an image processing apparatus, a control method thereof, and a control program thereof.
2. Description of the Related Art
For the purpose of preventing inappropriate photocopying, there is conventionally used the approach of forming the so-called ground tint on a paper sheet so that indication such as a character string of “COPY PROHIBITED” appears when the document is subjected to a photocopying process.
The ground tint includes, for example, a background, and a latent image constituting information such as character string set forth above. The ground tint is provided in a manner so as to ensure concealment of the indication such as the character string set forth above on the sheet where the ground tint is provided, and so as to render the character string legible through a photocopying process.
Such techniques related to ground tints are disclosed in various conventional documents.
For example, Japanese Laid-Open Patent Publication No. 2002-077571 discloses an image data output apparatus that automatically selects a ground tint pattern corresponding to the property of the printer from which an image is to be output (output resolution, color or monochrome photocopy, tone, and the like).
Japanese Laid-Open Patent Publication No. 2004-304597 discloses an image formation apparatus that has a latent image laid out such that the latent image of a ground tint is located at a region identified as an underlying region with respect to the image that is the subject of printing (i.e. a region where characters and the like of the subject image of printing are not located).
Japanese Laid-Open Patent Publication No. 2002-248829 discloses an image processing apparatus that analyzes the PDL (Page Description Language) of the document to be output, and provides an output with the ground tint superimposed when the document is classified document.
Japanese Laid-Open Patent Publication Nos. 2004-223854 and 2004-228896 disclose an image processing apparatus that has the position of each of the group of dots included in the latent image region and/or background region of a ground tint controlled according to the bit value at the bit position corresponding to additional information.
When a ground tint is produced on a paper sheet, the pattern of dots and the like for each of the latent image and background is selected. In the conventional combination of a latent image and background, the gap present at the border between the latent image and background (the region where the pattern constituting the latent image and the pattern constituting the background are not printed) may become so large that the concealment of the contents constituting the latent image could not be ensured.
When a ground tint is to be formed on a paper sheet, it is desirable to ensure the concealment of the contents constituting the latent image on the sheet of the document that is to be subjected to a printing process. Conventionally, sufficient consideration was not taken of the reliability of concealment of the contents constituting the latent image.